Heart Valves Prostheses and Methods for Percutaneous Heart Valve Replacement

ABSTRACT

Prosthetic heart valve devices and associated methods for percutaneous heart valve replacement are disclosed herein. A transcatheter valve prosthesis configured in accordance herewith includes a frame having a valve support and one or more support arms coupled thereto. The one or more support arms are configured to extend from the second end of the valve support toward the first end when the valve prosthesis is in an expanded configuration. When deployed in the expanded configuration, the one or more support arms have a curvilinear shape, such as a substantially S-shape, that at least partially engages tissue at the native heart valve.

FIELD OF THE INVENTION

The present technology relates generally to heart valve prostheses andassociated methods. In particular, several embodiments are directed totranscatheter heart valve devices for percutaneous replacement of nativeheart valves, such as a mitral valve.

BACKGROUND OF THE INVENTION

The human heart is a four chambered, muscular organ that provides bloodcirculation through the body during a cardiac cycle. The four mainchambers include the right atria and right ventricle which supplies thepulmonary circulation, and the left atria and left ventricle whichsupplies oxygenated blood received from the lungs to the remaining body.To insure that blood flows in one direction through the heart,atrioventricular valves (tricuspid and mitral valves) are presentbetween the junctions of the atria and the ventricles, and semi-lunarvalves (pulmonary valve and aortic valve) govern the exits of theventricles leading to the lungs and the rest of the body. These valvescontain leaflets that open and shut in response to blood pressurechanges caused by the contraction and relaxation of the heart chambers.The leaflets move apart from each other to open and allow blood to flowdownstream of the valve, and coapt to close and prevent backflow orregurgitation in an upstream manner.

Diseases associated with heart valves, such as those caused by damage ora defect, can include stenosis and valvular insufficiency orregurgitation. For example, valvular stenosis causes the valve to becomenarrowed and hardened which can prevent blood flow to a downstream heartchamber to occur at the proper flow rate and cause the heart to workharder to pump the blood through the diseased valve. Valvularinsufficiency or regurgitation occurs when the valve does not closecompletely, allowing blood to flow backwards, thereby causing the heartto be less efficient. A diseased or damaged valve, which can becongenital, age-related, drug-induced, or in some instances, caused byinfection, can result in an enlarged, thickened heart that loseselasticity and efficiency. Some symptoms of heart valve diseases caninclude weakness, shortness of breath, dizziness, fainting,palpitations, anemia and edema, and blood clots which can increase thelikelihood of stroke or pulmonary embolism. Symptoms can often be severeenough to be debilitating and/or life threatening.

Prosthetic heart valves have been developed for repair and replacementof diseased and/or damaged heart valves. Such valves can bepercutaneously delivered and deployed at the site of the diseased heartvalve through catheter-based systems. Such prosthetic heart valves canbe delivered while in a low-profile or compressed/contracted arrangementso that the prosthetic valves can be contained within a sheath componentof a delivery catheter and advanced through the patient's vasculature.Once positioned at the treatment site, the prosthetic valves can beexpanded to engage tissue at the diseased heart valve region to, forinstance, hold the prosthetic valve in position. While these prostheticvalves offer minimally invasive methods for heart valve repair and/orreplacement, challenges remain to provide prosthetic valves that preventleakage between the implanted prosthetic valve and the surroundingtissue (paravalvular leakage) and for preventing movement and/ormigration of the prosthetic valve that could occur during the cardiaccycle. For example, the mitral valve presents numerous challenges, suchas prosthetic valve dislodgement or improper placement due to thepresence of chordae tendinae and remnant leaflets, leading to valveimpingement. Additional challenges can include providing a prostheticvalve that resists pre-mature failure of various components that canoccur when subjected to the distorting forces imparted by the nativeanatomy and during the cardiac cycle. Further anatomical challengesassociated with treatment of a mitral valve include providing aprosthetic valve to accommodate the oval or kidney shape. Moreover, thekidney-shaped mitral valve annulus has muscle only along the exteriorwall of the valve with only a thin vessel wall that separates the mitralvalve and the aortic valve. This anatomical muscle distribution, alongwith the high pressures experienced on the left ventricular contraction,can be problematic for mitral valve prosthesis.

BRIEF SUMMARY OF THE INVENTION

Embodiments hereof are directed to heart valve prostheses and methods ofpercutaneous implantation thereof. The heart valve prostheses have acompressed configuration for delivery via a vasculature or other bodylumens to a native heart valve of a patient and an expandedconfiguration for deployment within the native heart valve. In anembodiment, the heart valve prosthesis may include a frame having avalve support that is configured to hold a prosthetic valve componenttherein, and a plurality of support arms extending from the valvesupport such that when the heart valve prosthesis is in the expandedconfiguration the plurality of support arms are configured to extendtoward the first end of the valve support for engaging a subannularsurface of the native heart valve. One or more of the plurality ofsupport arms comprises a curvilinear-shaped support arm, thecurvilinear-shaped support arm being formed to have opposing first andsecond arcuate regions longitudinally separated by a straight regionextending therebetween, with the first arcuate region being formed tocurve toward the valve support proximate a downstream portion thereof,the straight region being formed to slant toward the valve support whilejoining the first arcuate region and the second arcuate region, and thesecond arcuate region being formed to curve away from the valve supportproximate an upstream portion thereof.

In another embodiment, a heart valve prosthesis for implantation at anative valve region of a heart includes a valve support having anupstream portion and a downstream portion, the valve support beingconfigured to retain a prosthetic valve component therein and having aplurality of support arms extending from the downstream portion of thevalve support. When the heart valve prosthesis is in an expandedconfiguration, each support arm is configured to extend from thedownstream portion toward the upstream portion and to have a curvilinearshape with a first curved region having a first radius of curvature, asecond curved region having a second radius of curvature and an elongateregion extending between the first curved region and the second curvedregion. In such supports arms, the curvilinear shape is configured toabsorb distorting forces exerted thereon by the native valve region.

In another embodiment, a heart valve prosthesis for treating a nativemitral valve of a patient is disclosed. The heart valve prosthesisincludes a cylindrical support having an upstream portion, a downstreamportion and a first cross-sectional dimension, wherein the cylindricalsupport is configured to hold a prosthetic valve component that inhibitsretrograde blood flow. A plurality of S-shaped support arms extend fromthe downstream portion of the cylindrical support, such that when theheart valve prosthesis is in an expanded configuration the S-shapedsupport arms are configured to extend in an upstream direction to engagecardiac tissue on or below an annulus of the native mitral valve. Aradially-extending segment extends from the upstream portion of thecylindrical support and is of a second cross-sectional dimension greaterthan the first cross-sectional dimension. The radially-extending segmentis configured to engage cardiac tissue on or above the annulus of thenative mitral valve such that when the heart valve prosthesis is in theexpanded configuration and deployed at the native mitral valve, theannulus is positioned between upstream curved segments of the S-shapedsupport arms and the radially-extending segment.

BRIEF DESCRIPTION OF DRAWINGS

The foregoing and other features and aspects of the present technologycan be better understood from the following description of embodimentsand as illustrated in the accompanying drawings. The accompanyingdrawings, which are incorporated herein and form a part of thespecification, further serve to illustrate the principles of the presenttechnology. The components in the drawings are not necessarily to scale.

FIG. 1 is a schematic sectional illustration of a mammalian heart havingnative valve structures.

FIG. 2A is a schematic sectional illustration of a left ventricle of amammalian heart showing anatomical structures and a native mitral valve.

FIG. 2B is a schematic sectional illustration of the left ventricle of aheart having a prolapsed mitral valve in which the leaflets do notsufficiently coapt and which is suitable for replacement with variousembodiments of prosthetic heart valves in accordance with the presenttechnology.

FIG. 3 is a schematic illustration of a superior view a mitral valveisolated from the surrounding heart structures and showing the annulusand native leaflets.

FIG. 4A is a side view of a heart valve prosthesis in a deployed orexpanded configuration (e.g., a deployed state) in accordance with anembodiment of the present technology.

FIG. 4B is a top view of the heart valve prosthesis of FIG. 4A inaccordance with an embodiment of the present technology.

FIG. 4C is a top view of the heart valve prosthesis taken along lines4C-4C of FIG. 4A and in accordance with an embodiment of the presenttechnology.

FIG. 5A illustrates a cut-away view of a heart showing a partial sideview of a heart valve prosthesis implanted at a native mitral valve inaccordance with an embodiment of the present technology.

FIG. 5B is an enlarged sectional view of the heart valve prosthesis ofFIG. 5A shown in a deployed configuration (e.g., expanded state) inaccordance with an embodiment of the present technology.

FIG. 5C is an enlarged sectional view of a portion of a heart valveprosthesis shown in a deployed configuration (e.g., expanded state) inaccordance with another embodiment of the present technology.

FIGS. 6A-6C are side views of a variety of support arm configurations inaccordance with additional embodiments of the present technology.

FIG. 7 is a partial side view of a heart valve prosthesis showing aplurality of flexible regions on a support arm in accordance with anembodiment of the present technology.

FIGS. 8A-8H are side views of various support arms flexing in responseto a distorting force in accordance with further embodiments of thepresent technology.

FIG. 9 is an enlarged sectional view of the heart valve prosthesis ofFIGS. 5A-5B shown in a delivery configuration (e.g., low-profile orradially compressed state) in accordance with an embodiment of thepresent technology.

FIG. 10 is a sectional view of the heart illustrating a step of a methodof implanting a heart valve prosthesis using a trans-septal approach inaccordance with another embodiment of the present technology.

DETAILED DESCRIPTION OF THE INVENTION

Specific embodiments of the present technology are now described withreference to the figures, wherein like reference numbers indicateidentical or functionally similar elements. The terms “distal” and“proximal” are used in the following description with respect to aposition or direction relative to the treating clinician or with respectto a prosthetic heart valve device. For example, “distal” or “distally”are a position distant from or in a direction away from the clinicianwhen referring to delivery procedures or along a vasculature. Likewise,“proximal” and “proximally” are a position near or in a direction towardthe clinician. With respect to a prosthetic heart valve device, theterms “proximal” and “distal” can refer to the location of portions ofthe device with respect to the direction of blood flow. For example,proximal can refer to an upstream position or a position of bloodinflow, and distal can refer to a downstream position or a position ofblood outflow.

The following detailed description is merely exemplary in nature and isnot intended to limit the present technology or the application and usesof the present technology. Although the description of embodimentshereof are in the context of treatment of heart valves and particularlya mitral valve, the present technology may also be used in any otherbody passageways where it is deemed useful. Furthermore, there is nointention to be bound by any expressed or implied theory presented inthe preceding technical field, background, brief summary or thefollowing detailed description.

Embodiments of the present technology as described herein can becombined in many ways to treat one or more of many valves of the bodyincluding valves of the heart such as the mitral valve. The embodimentsof the present technology can be therapeutically combined with manyknown surgeries and procedures, for example, such embodiments can becombined with known methods of accessing the valves of the heart such asthe mitral valve with antegrade or retrograde approaches, andcombinations thereof.

FIG. 1 is a schematic sectional illustration of a mammalian heart 10that depicts the four heart chambers (right atria RA, right ventricleRV, left atria LA, left ventricle LV) and native valve structures(tricuspid valve TV, mitral valve MV, pulmonary valve PV, aortic valveAV). FIG. 2A is a schematic sectional illustration of a left ventricleLV of a mammalian heart 10 showing anatomical structures and a nativemitral valve MV. Referring to FIGS. 1 and 2A together, the heart 10comprises the left atrium LA that receives oxygenated blood from thelungs via the pulmonary veins. The left atrium LA pumps the oxygenatedblood through the mitral valve MV and into the left ventricle LV duringventricular diastole. The left ventricle LV contracts during systole andblood flows outwardly through the aortic valve AV, into the aorta and tothe remainder of the body.

In a healthy heart, the leaflets LF of the mitral valve MV meet evenlyat the free edges or “coapt” to close and prevent back flow of bloodduring contraction of the left ventricle LV (FIG. 2A). Referring to FIG.2A, the leaflets LF attach the surrounding heart structure via a fibrousring of connective tissue called an annulus AN. The flexible leaflettissue of the mitral leaflets LF are connected to papillary muscles PM,which extend upwardly from the lower wall of the left ventricle LV andthe interventricular septum IVS, via branching tendons called chordaetendinae CT. In a heart 10 having a prolapsed mitral valve MV in whichthe leaflets LF do not sufficiently coapt or meet, as shown in FIG. 2B,leakage from the left ventricle LV into the left atrium LA will occur.Several structural defects can cause the mitral leaflets LF to prolapseand regurgitation to occur, including ruptured chordae tendinae CT,impairment of papillary muscles PM (e.g., due to ischemic heartdisease), and enlargement of the heart and/or mitral valve annulus AN(e.g., cardiomyopathy).

FIG. 3 is a superior view of a mitral valve MV isolated from thesurrounding heart structures and further illustrating the shape andrelative sizes of the leaflets LF and annulus AN. As shown, the mitralvalve MV generally has a “D” or kidney shape. The mitral valve MVincludes an anterior leaflet AL which meets a posterior leaflet PL at acoaptation line when closed. When the anterior leaflet AL and posteriorleaflet PL fail to meet, regurgitation between the leaflets AL, PL or atcommissures C at the corners between the leaflets can occur.

Embodiments of prosthetic heart valve devices and associated methods inaccordance with the present technology are described in this sectionwith reference to FIGS. 4A-10. It will be appreciated that specificelements, substructures, uses, advantages, and/or other aspects of theembodiments described herein and with reference to FIGS. 4A-10 can besuitably interchanged, substituted or otherwise configured with oneanother in accordance with additional embodiments of the presenttechnology.

Provided herein are systems, devices and methods suitable forpercutaneous delivery and implantation of prosthetic heart valves in aheart of a patient. In some embodiments, methods and devices arepresented for the treatment of valve disease by minimally invasiveimplantation of artificial or prosthetic heart valves. For example, aprosthetic heart valve device, in accordance with embodiments describedherein, can be implanted for replacement of a diseased or damaged nativemitral valve or prior implanted prosthetic mitral valve in a patient,such as in a patient suffering from a prolapsed mitral valve illustratedin FIG. 2A. In further embodiments, the device is suitable forimplantation and replacement of other diseased or damaged heart valvesor prior implanted prosthetic heart valves, such as tricuspid, pulmonaryand aortic heart valves.

FIG. 4A is a side view of a heart valve prosthesis or a prosthetic heartvalve device 100 in a radially expanded or deployed configuration (e.g.,a deployed state) in accordance with an embodiment of the presenttechnology. FIG. 4B is a top view of the heart valve prosthesis 100 asconfigured in FIG. 4A, and FIG. 4C is a top view of the prosthesis 100taken along lines C-C of FIG. 4A. Referring to FIGS. 4A-4C together, theheart valve prosthesis 100 includes a frame or stent-like supportstructure 110 that includes a tubular portion or structural valvesupport 120 that defines a lumen 121 for retaining, holding and/orsecuring a prosthetic valve component 130 therein. The valve support 120can be generally cylindrical in shape having an upstream portion 124 ata first end 125 and a downstream portion 126 at a second end 127 thatare oriented along a longitudinal axis L_(A) of the valve support 120(FIG. 4A). The frame 110 further includes one or more support arms 140extending radially outward from the valve support 120 and generally inan upstream direction from the downstream portion 126 of the valvesupport 120 (e.g., to reach behind native leaflets of the mitral valveand engage cardiac tissue in the subannular region within the leftventricle). At least some of the support arms 140 can have a curvilinearshape 141 configured to atraumatically engage the native annulus andsubstantially absorb distorting forces such that the prosthesis 100 issupported by the annulus when prosthetic valve component 130 is closedduring systole.

In some embodiments, and as shown in the radially expanded configurationof FIG. 4A, the frame 110 further includes a radially-extending segmentor radial extension portion 150 at least partially surrounding andextending from the upstream portion 124 of the valve support 120. Theradially-extending segment 150 can include a plurality of self-expandingstruts 152 configured to radially expand when the prosthesis 100 isdeployed to the expanded configuration. In some arrangements, theradially-extending segment 150 can engage tissue on or above the annuluswhen implanted within a native mitral valve space. In this embodiment,the radially-extending segment 150 can retain the valve support 120 in adesired position within the native valve region (e.g., between thenative leaflets and annulus of the mitral valve). Referring to FIG. 4B,the radially-extending segment 150 and/or the valve support 120 caninclude a sealing material 160 that can extend around an upper orupstream surface 154 or a lower or downstream surface 155 (FIG. 4A) ofthe radially-extending segment 150, and/or around an interior wall 122or an exterior wall 123 of the valve support 120 to prevent leakage ofblood (e.g., paravalvular leakage) between the implanted prosthesis 100and the native heart tissue.

Referring to FIG. 4B, the radially-extending segment 150 and valvesupport 120 are shown having generally circular cross-sectional shapeswith the radially-extending segment 150 having a cross-sectionaldimension D₁ that is greater than a cross-sectional dimension D₂ of thevalve support 120. In some embodiments, the radially-extending segment150, the valve support 120 or both can have other cross-sectionalshapes, such as to accommodate the D-shaped or kidney-shaped mitralvalve. For example, the radially-extending segment 150 and/or valvesupport 120 may expand to an irregular, non-cylindrical, or oval-shapedconfiguration for accommodating the mitral valve or other valves.Furthermore, the native valves (e.g., mitral, aortic) can be uniquelysized and/or have other unique anatomical shapes and features that varybetween patients, and the prosthesis 100 for replacing or repairing suchvalves can be suitable for adapting to the size, geometry and otheranatomical features of such native valves. For example, theradially-extending segment 150 can expand within the native heart valveregion while simultaneously being flexible so as to conform to theregion engaged by the radially-extending segment 150.

FIGS. 4A and 4B show the radially-extending segment 150 having theplurality of struts 152 that outwardly extend from the exterior wall 123at the first end 125 of the valve support 120. In one embodiment, thestruts 152 are arranged relatively evenly about a circumference of thevalve support 120, and individual struts 152 join an adjacent strut 152at a crown 156. In one embodiment the crowns 156 have an atraumatic tip157 that prevents injury to the cardiac tissue during deployment andthrough the cardiac cycle. Examples of suitable radially-extendingsegments 150 are described in U.S. Patent Publication No. 2015/0119982,which is incorporated herein by reference in its entirety.

Referring back to FIGS. 4A and 4C, a plurality of support arms 140extend from the downstream portion 126 of the valve support 120, and aregenerally evenly spaced about the circumference of the exterior wall 123of the valve support 120 (FIG. 4C). In alternative arrangements, notshown, the support arms 140 can be unevenly spaced, grouped, irregularlyspaced, etc. about the circumference. In a particular example, thesupport arms 140 can be grouped closer together and extend from thevalve support 120 at positions that generally align with the anteriorand posterior leaflets of the mitral valve when deployed. The embodimentshown in FIG. 4C has twelve support arms 140 evenly spaced about thecircumference of the valve support 120. In alternative arrangements, theprosthesis 100 can include less than 12 support arms 140, e.g., twosupport arms, two to six support arms, greater than six support arms,nine support arms, etc., or more than twelve support arms 140.

Referring to FIG. 4A, the support arms 140 may extend from the valvesupport 120 at or near the second end 127 and may be described asextending generally toward the upstream portion 124 along or in parallelwith the exterior wall 123 of the valve support 120. As shown, thesupport arm 140 can have the generally curvilinear shape 141 or similargeometry. The curvilinear shape 141 includes opposing arcuate or curvedregions 142, 144 longitudinally separated by a slanted elongate orstraight region 143 that extends therebetween. When positioned for usewithin a native mitral valve, arcuate region 142 of a curvilinearsupport arm 140 may be referred to as a downstream curved segment 142and arcuate region 144 of the curvilinear support arm 140 may bereferred to as an upstream curved segment 144.

In some embodiments, the curvilinear shape 141 includes a first arcuate(e.g., curved) region 142 formed to curve in a direction toward theexterior wall 123 to engage a portion of at least one leaflet of thenative heart valve or other structures in the heart valve region, suchas chordae tendinae. In one embodiment, the first arcuate region 142 mayextend around a downstream edge of the native valve leaflet. In a medialsection of the support arm 140, the support arm includes the straightregion 143 configured to follow from the first arcuate region 142 and toslant in a direction toward the exterior wall 123 at an intermediate ormiddle portion 170 of the valve support 120. In a free-end section ofthe support arm 140 proximate the first end 125 of the valve support120, and following the straight or elongate region 143 along thecurvilinear shape 141, the support arm 140 further includes a secondarcuate (e.g., curved) region 144 formed to curve in a direction awayfrom the exterior wall 123 of the valve support 120 and to engage tissueat or proximate to the native heart valve when implanted. In aparticular example, the second arcuate region 144 can engage subannulartissue and/or portions of a heart chamber wall, e.g., a ventricularwall, in an atraumatic matter. In reference to FIG. 4A, and in aparticular embodiment, the first arcuate region 142 is longitudinallyseparated from the second arcuate region 144 by the straight or elongateregion 143 to form or define a substantially S-shaped profile.

In the embodiment shown in FIGS. 4A and 4C, the second arcuate region144 on each of the support arms 140 provides or defines a contact areaor landing zone 145 that is configured to atraumatically engage tissueat or near the subannular tissue so as to inhibit tissue erosion and/orresist movement of the prosthesis 100 in an upstream direction duringventricular systole, as is described further herein. As illustrated, thesecond arcuate region 144 includes a widened and/or flattened portion446 that forms the landing zone 145. As shown in FIG. 4A, the widenedportion 446 has a first width W₁ that is greater than a width W₂ at thefirst arcuate region 142 of the support arm 140. When the prosthesis 100is deployed and in contact with tissue (e.g., subannular tissue, nativeleaflets, ventricle wall, etc.) via the widened portion 446, the landingzone 145 effectively distributes native tissue contact over a greatersurface area to inhibit tissue erosion and to distribute load stress onthe support arms 140. In the embodiment shown in FIGS. 4A and 4C, thelanding zone 145 includes grooves 447 formed along the widened portion446 that can provide additional barriers against movement of the landingzone 145 with respect to the contacted tissue. In alternativearrangements, the landing zone 145 can include raised portions, bumps,cut-outs and other features that provide additional movement resistanceagainst the contacted tissue once deployed. In various arrangements, byresisting movement of the landing zone 145 against the contacted nativetissue, the support arms 140 provide atraumatic contact in a manner thatlimits or inhibits tissue erosion and/or abrasion following implantationof the prosthesis 100. In certain embodiments, and as shown in FIGS. 4Aand 4C, the support arm 140 includes an arm tip 148 that can be roundedor otherwise atraumatic to cardiac tissue engaged by the arm tip 148either during deployment or when fully implanted. In the illustratedembodiment, the arm tip 148 includes a hole 448 for attaching thesupport arms 140 to a delivery catheter (not shown) in aradially-compressed configuration for delivery to a target site.Additionally, or alternatively, one or more of the holes 448 may befilled with a secondary material (e.g. Tantalum, Platinum, Gold) forimproved visibility during fluoroscopy-guided delivery. In alternativearrangements, the support arms 140 may not include a hole 448 and/orother landing zone features (e.g., grooves 447) without departing fromthe scope hereof.

In some embodiments described herein, and in order to transform orself-expand between an initial compressed configuration (e.g., in adelivery state, not shown) and the deployed configuration (FIG. 4A), theframe 110 is formed from a resilient or shape memory material, such as anickel titanium alloy (e.g., nitinol), that has a mechanical memory toreturn to the deployed or expanded configuration. In one embodiment, theframe 110 can be a unitary structure that defines the radially-extendingsegment 150 at the inflow portion of the prosthesis 100, the valvesupport 120 and the plurality of support arms 140, and the frame 110 sodescribed may be made from stainless steel, a pseudo-elastic metal suchas nickel titanium alloy or nitinol, or a so-called super alloy, whichmay have a base metal of nickel, cobalt, chromium, or other metal. Insome arrangements, the frame 110 can be formed as a unitary structure,for e.g., from a laser cut, fenestrated, nitinol or other metal tube.Mechanical memory may be imparted to the structure that forms the frame110 by thermal treatment to achieve a spring temper in the stainlesssteel, for example, or to set a shape memory in a susceptible metalalloy, such as nitinol. The frame 110 may also include polymers orcombinations of metals, polymers or other materials.

In one embodiment, the frame 110 can be a flexible metal frame orsupport structure having a plurality of ribs and/or struts (e.g., struts128, 152) geometrically arranged to provide a latticework capable ofbeing radially compressed (e.g., in a delivery state, not shown) fordelivery to a target native valve site, and capable of radiallyexpanding (e.g., to the radially expanded configuration shown in FIG.4A) for deployment and implantation at the target native valve site.Referring to the valve support 120 shown in FIG. 4A, the ribs and struts128 can be arranged in a plurality of geometrical patterns that canexpand or flex and contract while providing sufficient resilience andstrength for maintaining the integrity of the prosthetic valve component130 housed within. For example, the struts 128 can be arranged in acircumferential pattern about the longitudinal axis L_(A), wherein thecircumferential pattern includes a series of diamond, zig-zagged,sinusoidal, or other geometric shapes.

In other embodiments, the frame 110 can include separately manufacturedcomponents that are coupled, linked, welded, or otherwise mechanicallyattached to one another to form the frame 110. For example, theradially-extending segment 150 can be coupled to the upstream portion124 of the valve support 120 (e.g., at attachments points 129 a on thestruts 128 as defined by a diamond-shaped geometry of the valve support120). Likewise, the support arms 140 can be coupled to the downstreamportion 126 of the valve support 120 (e.g., at attachment points 129 bon the struts 128 as defined by the diamond-shaped geometry of the valvesupport 120). Other arrangements and attachment points are contemplatedfor coupling one or more of the support arms 140 and radially-extendingsegment 150 to the valve support 120. In particular embodiments, and asshown in FIG. 4A, the support arms 140 can be coupled to the valvesupport 120 via an arm post 146. In one embodiment, the arm post 146 canbe integral with the frame 110 such that the arm post 146 is anextension of one or more struts 128. In another embodiment, the armposts 146 and valve support 120 may be coupled by a variety of methodsknown in the art, e.g., soldering, welding, bonding, rivets or otherfasteners, mechanical interlocking, or any combination thereof. In oneembodiment, the valve support 120 can be a balloon-expandable tubularmetal stent, and the radially-extending segment 150 and the support arms140 of the frame 110 may be formed from material and by methods so as tobe self-expanding as described above. In another embodiment inaccordance herewith, support arms 140 may extend from or be coupled toan intermediate or middle portion 170 of the valve support 120 withoutdeparting from the scope hereof

Referring to FIGS. 4B-4C, the prosthetic valve component 130 may becoupled to the interior wall 122 of the valve support 120 for governingblood flow through the heart valve prosthesis 100. For example, theprosthetic valve component 130 can include a plurality of leaflets 132(shown individually as 132 a-b) that coapt and are configured to allowblood flow through the prosthesis 100 in a downstream direction (e.g.,from the first end 125 to the second end 127) and inhibit blood flow inan upstream direction (e.g., from the second end 127 to the first end125). While the prosthetic valve component 130 is shown having abicuspid arrangement, it is understood that the prosthetic valvecomponent 130 can have three leaflets 132 (tricuspid arrangement, notshown) or more than three leaflets 132 that coapt to close theprosthetic valve component 130. In one embodiment, the leaflets 132 canbe formed of bovine pericardium or other natural material (e.g.,obtained from heart valves, aortic roots, aortic walls, aortic leaflets,pericardial tissue, such as pericardial patches, bypass grafts, bloodvessels, intestinal submucosal tissue, umbilical tissue and the likefrom humans or animals) that are mounted to the interior wall 122 of thevalve support 120. In another embodiment, synthetic materials suitablefor use as valve leaflets 132 include DACRON® polyester (commerciallyavailable from Invista North America S.A.R.L. of Wilmington, Del.),other cloth materials, nylon blends, polymeric materials, and vacuumdeposition nitinol fabricated materials. In yet a further embodiment,valve leaflets 132 can be made of an ultra-high molecular weightpolyethylene material commercially available under the trade designationDYNEEMA from Royal DSM of the Netherlands. With certain leafletmaterials, it may be desirable to coat one or both sides of the leafletwith a material that will prevent or minimize overgrowth. It can befurther desirable that the leaflet material is durable and not subjectto stretching, deforming, or fatigue.

FIG. 5A is a schematic illustration showing a partial side view theprosthesis 100 implanted at a native mitral valve region of the heart 10in accordance with an embodiment of the present technology. Theprosthesis 100 is shown in FIG. 5A having only two support arms 140 forpurposes of illustration only. It is understood that the prosthesis 100,in some arrangements, can have more than two support arms 140, e.g.,greater than six support arms, etc. Generally, when implanted, theupstream portion 124 of the valve support 120 is oriented to receiveblood inflow from a first heart chamber, e.g., left atrium LA for mitralvalve MV replacement, left ventricle for aortic valve replacement, etc.,and the downstream portion 126 is oriented to release blood outflow intoa second heart chamber or structure, e.g., left ventricle LV for mitralvalve MV replacement, aorta for aortic valve replacement.

In operation, the heart valve prosthesis 100 can be intravascularlydelivered to a desired native valve region of the heart 10, such as nearthe mitral valve MV, while in the radially compressed configuration (notshown) and within a delivery catheter (not shown). Referring to FIG. 5A,the prosthesis 100 can be advanced to a position within or downstream ofthe native mitral valve annulus AN where the support arms 140 and thedownstream portion 126 of the valve support 120 are released from thedelivery catheter. The delivery catheter can then release the upstreamportion 124 of the valve support 120 and the radially-extending segment150 at a position within or upstream of the native mitral valve MV so asto enlarge toward the radially expanded configuration and engage thenative tissue within the native heart valve region. Once released fromthe delivery catheter, the prosthesis 100 can be positioned such thatthe radially-extending segment 150 resides within the left atrium andengages tissue at or near the supra-annular region. The prosthesis 100is further positioned such that the support arms 140 engageoutward-facing surfaces of the native leaflets LF to capture theleaflets between the support arms 140 and the exterior wall 123 of thevalve support 120. The contact area or landing zone 145 of each of thesupport arms 140 is configured to engage tissue at or near thesubannular tissue so as to resist movement of the prosthesis 100 in anupstream direction during ventricular systole, as is described furtherherein.

FIG. 5B is an enlarged sectional view of the heart valve prosthesis 100of FIG. 5A shown in a radially expanded configuration (e.g., a deployedstate) and in accordance with an embodiment of the present technology.In FIG. 5B, the prosthesis 100 is schematically shown positioned at amitral valve MV on the right-hand side of the illustration. Whendeployed and implanted, the heart valve prosthesis 100 is configured toposition the prosthetic valve component 130, which is retained or heldwithin the valve support 120, in a desired location and orientationwithin the native mitral valve MV. Referring to FIGS. 5A and 5Btogether, several features of the prosthesis 100 provide resistance tomovement of the prosthesis 100, promote tissue ingrowth, minimize orprevent paravalvular leakage and/or minimize native tissue erosion whenimplanted in the radially expanded configuration. For example, theradially-extending segment 150 can be positioned to expand within theatrial space above the mitral valve and engage cardiac tissue within theatrial space. In particular, at least a lower surface or apex 153 of anarching or S-shaped strut 152 can provide a tissue engaging region forcontacting the supra-annular tissue, for example to provide sealingagainst paravalvular leakage and to inhibit downstream migration of theprosthesis 100 relative to the native annulus.

In some embodiments, an upward oriented lip portion 158 of the struts152 that rise to form the crowns 156 can provide further tissue contactzones that can further inhibit downstream movement of the prosthesis 100relative to the native annulus, and inhibit rocking or side-to-siderotation of the prosthesis 100 within the native valve during thecardiac cycle, thereby inhibiting paravalvular leakage and assuringalignment of the prosthetic valve component 130 within the nativeannulus. In other embodiments, the radially-extending segment 150 can bea flange, a brim, a ring, finger-like projections or other projectioninto the atrial space for at least partially engaging tissue at or abovea supra-annular region thereof.

Referring to FIGS. 5A and 5B together, the support arms 140 are shownhaving the curvilinear shape 141 and extending from the downstreamportion 126 of the valve support 120. The support arms 140 areconfigured to engage both the native leaflets (if present) and/or thesubannular region of the mitral valve MV within the ventricular space.In one embodiment, the support arms 140 are configured to engage anoutside surface (e.g., ventricle-facing side) of the leaflet such thatthe native leaflet is captured between the support arm 140 and theexterior wall 123 of the valve support 120. In one such embodiment, thepreformed curvilinear shape 141 of the support arm 140, for example at atransitional apex 144 a of the second arcuate region 144, can be biasedtoward the exterior wall 123 of the valve support 120 such that acompressive force Fc₁ presses the leaflet LF against the exterior wall123 in a manner that pinches, grasps, crimps or otherwise confines theleaflet within the space 105 between the support arm 140 and theexterior wall 123 of the valve support 120.

To further inhibit upstream migration of the prosthesis 100 with respectto the native valve annulus AN, the second arcuate region 144 isconfigured to engage the subannular region (e.g., behind the leaflet LF)via the contact area or landing zone 145. In an additional embodiment,the second arcuate region 144 can contact tissues below the annulus AN,such as the ventricle wall (as shown in FIG. 5C). By contacting thesubannular region (FIGS. 5A and 5B) and/or the tissues below the annulusAN (FIG. 5C) via, for example, the widened portion 446 (FIGS. 4A and 4C)that extends to arm tip 148, the landing zone 145 distributes surfacecontact over a larger region to inhibit tissue erosion and to distributeload stress on the support arms 140 in an atraumatic manner.

In various arrangements, the curvilinear shape 141 of the support arm140 can form a substantially S-shaped profile. In certain arrangements,the support arms 140 can be more flexible (e.g., than other portions ofthe frame 110) and/or be made of resilient material (e.g., shape-memorymaterial, super-elastic material, etc.) that can absorb forces exertedon the support arms 140 when implanted in the heart 10 and during thecardiac cycle. For example, these forces can cause the substantiallyS-shaped profile to temporarily deform, deflect or otherwise changeshape. Likewise, the curvilinear shape 141 of the support arms canprovide compressive forces Fc₂ in an upstream direction (e.g., at thecontact zone 145) and against annulus tissue. In one embodiment, theapex 153 (e.g., lower surface) of the radially-extending segment 150 canbe longitudinally separated from the landing zone 145 of the secondarcuate region by a gap 106. When implanted, the gap 106 can be sized toreceive annular tissue therein. In one embodiment, the apex 153 of thearching strut 152 can provide a downward compressive force Fc₃ on thecontacted tissue of the annulus that opposes the compressive force F₂across the gap 106. Accordingly, the compressive forces Fc₂ and Fc₃ maybe aligned and/or opposed to each other such that annular tissue iscaptured between the radially-extending segment 150 and the support arms140 having the preformed curvilinear shape 141. In some embodiments, thestruts 152 can be circumferentially- and radially-aligned with thesecond arcuate region 144 of the support arms 140 such that thecompressive force Fc₁ is directly opposed to the compressive force Fc₃(shown in FIG. 5B) to effectively pinch the annulus AN therebetween.

In some embodiments, the portions of the prosthesis 100, such as theradially-extending segment 150, the valve support 120 and/or the supportarms 140 can be provided with a sealing material 160 (FIG. 4B) to coverat least portions of the prosthesis 100. The sealing material 160 canprevent paravalvular leakage as well as provide a medium for tissueingrowth following implantation, which can further provide biomechanicalretention of the prosthesis 100 in the desired deployment locationwithin the native heart valve region. In some embodiments, the sealingmaterial 160 or portions thereof may be a low-porosity woven fabric,such as polyester, DACRON® polyester, or polytetrafluoroethylene (PTFE),which creates a one-way fluid passage when attached to the frame 110. Inone embodiment, the sealing material 160 or portions thereof may be alooser knit or woven fabric, such as a polyester or PTFE knit, which canbe utilized when it is desired to provide a medium for tissue ingrowthand the ability for the fabric to stretch to conform to a curvedsurface. In another embodiment, polyester velour fabrics mayalternatively be used for at least portions of the sealing material 160,such as when it is desired to provide a medium for tissue ingrowth onone side and a smooth surface on the other side. These and otherappropriate cardiovascular fabrics are commercially available from BardPeripheral Vascular, Inc. of Tempe, Ariz., for example. In anotherembodiment, the sealing material 160 or portions thereof may be anatural graft material, such as pericardium or another membranoustissue.

FIGS. 6A-6C are side views of a variety of support arm configurations inaccordance with additional embodiments of the present technology.Referring to FIGS. 6A-6C together, the support arm 140, in oneembodiment, can generally have the curvilinear shape 141 with first andsecond arcuate regions 142, 144 separated by an elongate orsubstantially straight region 143 that together extend substantially inparallel with a longitudinal axis 601 (e.g., generally aligned with thelongitudinal axis L_(a) of the valve support 120; FIG. 5B). In someembodiments, the support arm 140 has an S-shaped profile. As illustratedin FIGS. 6A-6C, the first arcuate region 142 can have a first radius ofcurvature R₁ and the second arcuate region 144 can have a second radiusof curvature R₂ that, in certain embodiments, is (a) substantially equalto the first radius of curvature R₁ (FIG. 6A), (b) substantially lessthan the first radius of curvature R₁ (FIG. 6B), or is (c) substantiallygreater than the first radius of curvature R₁ (FIG. 6C).

Referring to FIGS. 5B and 6A-6C together, the second arcuate region 144can have the tissue engaging portion or contact zone 145 for engagingsubannular or other cardiac tissue during and/or after deployment. Inthe embodiments illustrated in FIGS. 6A-6D, the support arm 140 includesthe arm post 146 at a first end 140 a and from which the first arcuateregion 142 generally extends in the outward direction from thelongitudinal axis L_(A), 601 and in radial alignment with the downstreamportion 126 of the valve support 120 (FIG. 5B). The first arcuate region142 curves about a first center of curvature C_(C1). As shown in FIG.6A, the substantially straight or elongate portion 143 extends betweenthe first arcuate region 142 and the second arcuate region 144. Thesecond arcuate region 144 is radially aligned with an intermediate ormiddle portion 170 of the valve support 120 between the upstream anddownstream portions 124, 126 (FIG. 5B). In one embodiment, the secondarcuate region 144 curves about a second center of curvature C_(C2). Inthe embodiments illustrated in FIGS. 5B and 6A-6C, a first axis line(not shown) drawn through the first center of curvature C_(C1) isparallel to a second axis line (not shown) drawn through the secondcenter of curvature C_(C2). The first and second axis lines aresubstantially perpendicular to the longitudinal axis L_(A), 601 (FIG.6A).

Referring to FIG. 6A, and in some embodiments, the arm post 146 can begenerally linear and have a suitable length L₁ for extending the firstarcuate region 142 a desirable distance downstream from a connection(not shown) to the valve support 120. In some embodiments, the arm post146 can be generally parallel to the longitudinal axis L_(A) of theprosthesis 100 and/or valve support 120 (shown in FIG. 5B). Followingthe general curvature of the first arcuate region 142 shown in FIG. 6A,a first curved segment 610 of the region 142 extends radially outwardfrom the arm post 146. More particularly, the first curved segment 610may be described as arcuate or generally curved in an outward anddownstream direction until it reaches a transitional apex 142 a of thefirst arcuate region 142. Thereafter a second curved segment 614 of thefirst arcuate region 142 continues the curve profile and extends outwardand in a generally upstream direction from the transitional apex 142 a.

As shown in FIG. 6A, a first transitional point 616 initiates theelongate region 143 of the support arm 140, with the elongate region 143slanting and extending in an upward and inward direction relative to thelongitudinal axis L_(A) of the valve support 120 to end at a secondtransitional point 618. In similar fashion, the general curvature of thesecond arcuate region 144 initiates as the second transitional point 618such that following the curvature of the second arcuate region 144, athird curved segment 620 is defined that generally curves in an outwardand upstream direction to reach a transitional apex 144 a of the secondarcuate region 144. A fourth curved segment 622 of the second arcuateregion 144 continues the curve profile and extends (e.g., relative tothe longitudinal axis LA) from the transitional apex 144 a in an outwarddirection and can also curve slightly downstream toward a free-end orarm tip 148. An opening 624 between the second arcuate region 144 andthe first arcuate region 142 of the support arm 140 is generally createdin the space between the third transition 618 and the first end 140 a ofthe support arm 140, and can be configured to receive a native leafletLF and/or chordae tendinae therein. Other embodiments of support arms140 can have curved segments 610, 614, 620 and 622 with less curvatureor greater curvature. Additionally, the embodiments of support arms 140shown in FIGS. 5B and 6A-6D can have an overall height H₁ that is lessthan a height H₂ of the valve support 120 (FIGS. 5B and 6A). Otherarrangements and heights are also contemplated. Accordingly, in additionto the radius of curvature R₁, R₂ of the first and second arcuateregions 142, 144 and/or other geometric features/alterations, theoverall height H₁ of the support arm 140 can be selected to accommodatethe anatomy at the desired target location of the heart valve.

Referring again to FIG. 6A, the first and second arcuate regions 142,144 of the support arm 140 can be configured to absorb, translate and/ormitigate distorting forces present within the heart during, for example,systole and diastole. In particular arrangements, the support arms 140have a spring-type response to distorting forces (e.g., physical forcescapable of exerting on and changing a contour of the support arm 140).As described in more detail herein, the support arms 140 can havemultiple hinge points for flexing or absorbing such distorting forces.For example, a first distorting force can be absorbed as a result of thespring-type response of the individual support arms 140 in a manner thatelastically or reversibly and temporarily distorts the unbiasedconfiguration of the support arm 140. As the first distorting forcedissipates (e.g., during the cardiac cycle), the spring-type motioncontinues with the transition of the support arm contour from thedistorted position back to an unbiased configuration. Accordingly, aspring-type response of the support arm 140 occurs in a manner that iscounter to the first distorting force. In these arrangements, the extentto which the support arm 140 is compressed and/or extended isproportional to the distorting force(s) exerted on the support arm. Thesupport arm 140 can have a selected stiffness which provides a constantfor the distance or delta of distortion (e.g., compression, distention).In certain arrangements, the support arms 140 can have constantstiffness along the entire length of the support arm and covering all ofthe multiple hinge points. In other arrangements, the support arms 140can have variable stiffness along the length of the support arm andencompassing the different hinge points. Such selectivity in thestiffness of the individual support arms 140 can provide prosthesisdesigns to accommodate unique and variable native structures, such asfor accommodating variable distorting forces exerted by the nativemitral valve region. Variable stiffness may be accomplished in a varietyof ways: i) differences in the support arm cross-sectional area, ii)variable cold working of select support arms in the case of conventionalelastic-plastic metals (e.g. stainless steel, titanium alloys,cobalt-chromium based alloys), and/or iii) selectively heating orproviding a heat treatment of one or more support arms and not others.

In particular embodiments, the shape and/or size of the first and secondarcuate regions 142, 144 can be selected to accommodate forces, such asradially compressive forces, e.g., exerted by the native annulus and/orleaflets Fa, longitudinal diastolic Fd and systolic Fs forces, hoopstress, etc. Absorption of the distorting forces can serve to preventtranslation of those forces to the valve support 120 and therebypreserve the coaptation of the prosthetic valve component 130.Additionally, and as further shown in FIG. 7, absorption of thedistorting forces along the entirety of the support arm 140 and/or atseveral hinge points or locations 701 (e.g., transitions 140 a, 142 a,616, 618 and 144 a) distribute the stress caused by the forces, therebysubstantially preventing fatigue of the support arms 140 and/orminimizing tissue erosion at contacted portions of the native anatomy.In accordance with the present technology, the support arms 140 mayflex, bend, rotate or twist under the distorting forces while the valvesupport 120 substantially maintains its rigidity and/or original shape(e.g., a generally circular shape).

FIGS. 8A-8H are side views of various support arms 140 flexing inresponse to a distorting force in accordance with further embodiments ofthe present technology. The degree of flexibility of individual supportarms 140 may be consistent among all support arms 140 of a prosthesis100, or, alternatively, some support arms 140 may be more flexible thanother support arms 140 on the same prosthesis 100. Likewise, a degree offlexibility of individual support arms 140 may be consistent throughoutan entire length of the support arm 140 or curvature of the first andsecond arcuate regions 142, 144. In other embodiments, however, thedegree of flexibility can vary along the length and/or curvature of eachsupport arm 140.

As shown FIGS. 8A-8H, the first and second arcuate regions 142, 144 ofthe support arms 140 may flex relative to the arm post 146, the valvesupport 120 (shown in dotted lines) and/or be configured to alter theirarcuate shape(s) in response to varying distorting forces F that can beapplied by the surrounding tissue during or after implantation of theprosthesis 100. From a static position (FIG. 8A), the first arcuateregion 142 may flex downward to a shape/position 842 b (FIG. 8B) inresponse to a downward force F₁ caused by, for example, chordal load(e.g., from chordal tendinae engaging the first arcuate region 142). Inanother embodiment, the second arcuate region 144 may flex downward andthe first arcuate region 142 may compress from the static position (FIG.8A) to shapes/positions 844 cand 842 c, respectively (FIG. 8C), inresponse to a downward force F₂ caused by, for example, a tip load(e.g., from left ventricle pressure). Similarly, the first and secondarcuate regions 142, 144 may flex or compress inward to shapes/positions842 d, 844 d (FIG. 8D) in response to laterally directed inward forcesF_(3a), F_(3b) caused by, for example, ventricle wall load (e.g., fromleft ventricle contraction). Engagement of the native annulus by thesecond arcuate region 144, resulting in force F₄, may flex and compressthe second arcuate region 144 inward to shape/position 844 e, which mayalso promote a position change in the first arcuate region to position842 e (FIG. 8E). In some embodiments, the first and second arcuateregions 142, 144 may flex, rotate inwardly/outwardly and/or deform inresponse to the laterally directed forces F_(3a), F_(3b), F₄, ordownward in response to the generally vertically directed forces F₁, F₂.

In other arrangements, and as shown in FIGS. 8F-8H, the first and secondarcuate regions 142, 144 shown in a static position in FIG. 8F may alsoflex and/or rotate laterally, for example, to positions 842 g/844 g(FIG. 8G) or 842 h/844 h (FIG. 8H) in response to a laterally-directedforce F₅, by bending at one or more transitions 140 a, 142 a, 616, 618and 144 a (FIG. 6A), for example, at unique and variable angles off amidline 802 such that the arm tips 148 may be splayed away from eachother.

FIG. 9 is an enlarged sectional view of the heart valve prosthesis 100of FIGS. 5A-5B shown in a compressed delivery configuration (e.g., alow-profile or radially compressed state) configured in accordance withan embodiment of the present technology. The prosthesis 100 can beconfigured for delivery within a delivery catheter sheath (not shown) inthe radially compressed configuration shown in FIG. 9. Moreparticularly, in the radially compressed configuration, theradially-extending segment 150 can be elongated, folded or otherwisearranged to longitudinally extend in a substantially straightened statefrom the valve support 120. Additionally, the plurality of support arms140 are longitudinally extended and arranged in a substantiallystraightened state for percutaneous delivery to the targeted nativeheart valve. As shown in FIG. 9, the support arms 140 can extend beyondthe second end 127 of the valve support 120 such that the first arcuateregion 142 is generally linear and substantially parallel with thelongitudinal axis L_(A), while the second arcuate region 144 remains ina curved profile. Upon release of the radial constraint, the supportarms 140 can move to an outward biased position as the delivery cathetersheath (not shown) is withdrawn and the radially-extending segment 150can self-expand to the radially expanded configuration (FIG. 5B).Additionally, in the event that the heart valve prosthesis 100 needs tobe repositioned, removed and/or replaced after implantation, theradially-extending segment 150 and the valve support 120 can transitionfrom the radially expanded configuration (e.g., the deployed state)(FIG. 5B) back to the radially contracted configuration (FIG. 9) using acatheter device or other lateral retaining sheath.

Access to the mitral valve or other atrioventricular valve can beaccomplished through a patient's vasculature in a percutaneous manner.Depending on the point of vascular access, the approach to the mitralvalve may be antegrade and may rely on entry into the left atrium bycrossing the inter-atrial septum. Alternatively, approach to the mitralvalve can be retrograde where the left ventricle is entered through theaortic valve or via a transapical puncture. Once percutaneous access isachieved, the interventional tools and supporting catheter(s) may beadvanced to the heart intravascularly and positioned adjacent the targetcardiac valve in a variety of manners. For example, the heart valveprosthesis 100 may be delivered to a native mitral valve region forrepair or replacement of the native valve via a transseptal approach(shown in FIG. 10), a retrograde approach through the aortic valve, orvia a transapical puncture. Suitable transapical and/or transatrialimplantation procedures that may be adapted for use with the heart valveprostheses 100 described herein are disclosed in U.S. Appl. No.13/572,842 filed Aug. 13, 2012 to Igor Kovalsky, U.S. Appl. Pub. No.2011/0208297 to Tuval et al., and U.S. Appl. Pub. No. 2012/0035722 toTuval et al, each of which is incorporated by reference herein in itsentirety.

FIG. 10 is a sectional view of the heart 10 illustrating a step of amethod of implanting a heart valve prosthesis 100 using a transseptalapproach in accordance with another embodiment of the presenttechnology. Referring to FIGS. 5A, 9 and 10 together, the prosthesis 100may be advanced into proximity to the mitral valve MV within a deliverycatheter 20. Optionally, a guidewire (not shown) may be used over whichthe delivery catheter 20 may be slidably advanced. A sheath 22 of thedelivery catheter 20, which contains the prosthesis 100 in a radiallycompressed configuration (shown in FIG. 9), is advanced through themitral valve annulus AN between native leaflets LF, as shown in FIG. 10.Referring to FIG. 10, the sheath 22 is then proximally retractedallowing the prosthesis 100 to expand such that the support arms 140 arein an outward position spatially separated from the longitudinal axisL_(A) and while the valve support 120 remains radially contracted. Inthis deployment phase, the outward movement of the support arms 140 isfacilitated by the shape-memory bias of the first arcuate region 142. Inthis transition phase, the first arcuate region 142 can have a thirdradius of curvature R₃ that is greater than the first radius ofcurvature R₁, whereas the second arcuate region 144 continues to havethe second radius of curvature R₂. The second arcuate region 144provides for atraumatic engagement of cardiac tissue during all phasesof deployment within the Mitral Valve MV (as shown in FIG. 10). Forexample, the second arcuate region 144 is configured to deflect inresponse to contact with chordae tendinae CT when transitioning betweenthe radially contracted configuration and the radially expandedconfiguration. The second arcuate region 144 can also atraumaticallyengage a wall of the left ventricle LV during deployment and as thesupport arm 140 moves or swings behind the native leaflets LF. When thesupport arms 140 are fully deployed (e.g., FIG. 5A), the support arms140 are positioned further inwardly relative to the longitudinal axisL_(A) and such that the leaflets LF are engaged between the support arms140 and the valve support 120. The sheath 22 may be further retracted torelease the valve support 120 and the radially-extending segment 150(e.g., within the space of the left atrium LA).

After the sheath 22 has been removed and the prosthesis 100 allowed toreturn to its deployed state, the delivery catheter 20 can still beconnected to the prosthesis 100 (e.g., system eyelets, not shown, areconnected to the prosthesis eyelets) so that the operator can furthercontrol the placement of the prosthesis 100 as it expands toward theradially expanded configuration. For example, the prosthesis 100 may beexpanded upstream or downstream of the target location then pusheddownstream or upstream, respectively, into the desired target locationbefore releasing the prosthesis 100 from delivery catheter 20. Once theprosthesis 100 is positioned at the target site, the delivery catheter20 may be retracted in a proximal direction and the prosthesis 100detached while in the radially expanded configuration at the nativetarget valve (e.g., mitral valve MV).

While various embodiments have been described above, it should beunderstood that they have been presented only as illustrations andexamples of the present technology, and not by way of limitation. Itwill be apparent to persons skilled in the relevant art that variouschanges in form and detail can be made therein without departing fromthe spirit and scope of the present technology. Thus, the breadth andscope of the present technology should not be limited by any of theabove-described embodiments, but should be defined only in accordancewith the appended claims and their equivalents. It will also beunderstood that each feature of each embodiment discussed herein, and ofeach reference cited herein, can be used in combination with thefeatures of any other embodiment. All patents and publications discussedherein are incorporated by reference herein in their entirety.

What is claimed is:
 1. A heart valve prosthesis having a compressedconfiguration for delivery within a vasculature and an expandedconfiguration for deployment within a native heart valve in a patient,comprising: a frame including a valve support having a first end and asecond end, the valve support being configured to hold a prostheticvalve component therein, and a plurality of support arms extending fromthe second end of the valve support, wherein when the heart valveprosthesis is in the expanded configuration, the plurality of supportarms are configured to extend toward the first end of the valve supportfor engaging a subannular surface of the native heart valve and one ormore of the plurality of support arms comprises a curvilinear-shapedsupport arm, the curvilinear-shaped support arm being formed to haveopposing first and second arcuate regions longitudinally separated by astraight region extending therebetween, with the first arcuate regionbeing formed to curve toward the valve support proximate the second end,the straight region being formed to slant toward the valve support whilejoining the first arcuate region and the second arcuate region, and thesecond arcuate region being formed to curve away from the valve supportproximate the first end.
 2. The heart valve prosthesis of claim 1,wherein the first and second arcuate regions and the straight region ofthe curvilinear-shaped support arm has a substantially S-shape.
 3. Theheart valve prosthesis of claim 1, wherein the second arcuate region ofthe curvilinear-shaped support arm defines a landing zone that isconfigured to atraumatically engage tissue at the native heart valve. 4.The heart valve prosthesis of claim 3, wherein a width of the landingzone is greater than a width of the remainder of the curvilinear-shapedsupport arm.
 5. The heart valve prosthesis of claim 3, wherein thelanding zone includes one or more tissue gripping features.
 6. The heartvalve prosthesis of claim 3, wherein the frame further comprises aradially-extending segment that radially extends from the first end ofthe valve support for engaging a supra-annular surface of the nativeheart valve, and wherein the radially-extending segment islongitudinally spaced from and opposed to the landing zone of thecurvilinear-shaped support arm when the heart valve prosthesis is in theexpanded configuration for securing the heart valve prosthesis to thenative heart valve.
 7. The heart valve prosthesis of claim 1, whereinthe first arcuate region of the curvilinear-shaped support arm has afirst radius of curvature and the second arcuate region of thecurvilinear-shaped support arm has a second radius of curvature that issubstantially equal to the first radius of curvature.
 8. The heart valveprosthesis of claim 1, wherein the first arcuate region of thecurvilinear-shaped support arm has a first radius of curvature and thesecond arcuate region of the curvilinear-shaped support arm has a secondradius of curvature that is greater than the first radius of curvature.9. The heart valve prosthesis of claim 1, wherein the first arcuateregion of the curvilinear-shaped support arm has a first radius ofcurvature and the second arcuate region of the curvilinear-shapedsupport arm has a second radius of curvature that is less than the firstradius of curvature.
 10. The heart valve prosthesis of claim 1, whereinthe native heart valve is a mitral valve having an annulus, and whereinthe second arcuate region of the curvilinear-shaped support arm isconfigured to engage a subannular surface of the annulus of the mitralvalve and a wall of a left ventricle.
 11. A heart valve prosthesis forimplantation at a native valve region of a heart, the prosthesiscomprising: a valve support having an upstream portion and a downstreamportion, the valve support configured to retain a prosthetic valvecomponent therein; and a plurality of support arms extending from thedownstream portion of the valve support, each support arm beingconfigured to extend from the downstream portion toward the upstreamportion when the heart valve prosthesis is in an expanded configuration,and wherein in the expanded configuration each of the plurality ofsupport arms has a curvilinear shape with a first curved region having afirst radius of curvature, a second curved region having a second radiusof curvature and an elongate region extending between the first curvedregion and the second curved region, wherein the curvilinear shape ofthe plurality of support arms is configured to absorb distorting forcesexerted thereon by the native valve region.
 12. The heart valveprosthesis of claim 11, wherein the curvilinear shape is substantiallyan S-shape.
 13. The heart valve prosthesis of claim 11, wherein firstcurved regions of the plurality of support arms extend in a downstreamdirection beyond a downstream end of the valve support.
 14. The heartvalve prosthesis of claim 11, further comprising: a radially-extendingsegment coupled to the upstream portion of the valve support, whereinwhen the heart valve prosthesis is in the expanded configuration theradially-extending segment is configured to engage a supra-annularsurface of the native valve region.
 15. The heart valve prosthesis ofclaim 14, wherein in the expanded configuration atraumatic landing zonesof the second curved regions of the plurality of support arms areconfigured to oppose the radially-extending segment such that acompressive force is exerted on an annulus at the native valve region bythe atraumatic landing zones and the radially-extending segment so as toinhibit movement of the heart valve prosthesis.
 16. The heart valveprosthesis of claim 15, wherein the native valve region is a mitralvalve and the annulus is a mitral valve annulus and wherein theatraumatic landing zones of the second curved regions of the pluralityof support arms are longitudinally spaced from the radially-extendingsegment such that the mitral valve annulus may be positionedtherebetween.
 17. The heart valve prosthesis of claim 14, furthercomprising: a sealing material extending over the radially-extendingsegment, the valve support, or both, wherein the sealing material isconfigured to inhibit paravalvular leaks.
 18. A heart valve prosthesisfor treating a native mitral valve of a patient, the prosthesiscomprising: a cylindrical support having an upstream portion, adownstream portion and a first cross-sectional dimension, wherein thecylindrical support is configured to hold a prosthetic valve componentthat inhibits retrograde blood flow; a plurality of S-shaped supportarms extending from the downstream portion of the cylindrical support,wherein when the heart valve prosthesis is in an expanded configurationthe S-shaped support arms are configured to extend in an upstreamdirection to engage cardiac tissue on or below an annulus of the nativemitral valve; and a radially-extending segment extending from theupstream portion of the cylindrical support and having a secondcross-sectional dimension greater than the first cross-sectionaldimension, the radially-extending segment being configured to engagecardiac tissue on or above the annulus of the native mitral valve. 19.The heart valve prosthesis of claim 18, wherein when the heart valveprosthesis is in the expanded configuration and deployed at the nativemitral valve, the annulus is positioned between upstream curved segmentsof the S-shaped support arms and the radially-extending segment.
 20. Theheart valve prosthesis of claim 19, wherein each S-shaped support armincludes a landing zone on its upstream curved segment that isconfigured to atraumatically engage cardiac tissue on or below theannulus of the native mitral valve.